1. Technical Field
The present disclosure relates to a vehicle seat including a frame-shaped seat frame, a seat pad for elastically supporting a passenger, and a planar body for supporting the seat pad from a backside, the seat pad being placed inside the seat frame.
2. Description of Related Art
In this type of vehicle seat, a planar body is provided in a stretched manner inside a seat frame forming a seat framework, and the planar body supports a seat pad for elastically supporting an occupant. The planar body is a face material having a moderate flexibility, and supports the seat pad from a backside while extending due to its own flexibility. In this type of configuration, the seat pad is pressed by an occupant in a sitting state so that the seat pad sinks downward. At this time, for example, a seat-pad portion that supports occupant buttocks (particularly, occupant hipbones) tends to largely sink by being strongly pressed. On this account, from the viewpoint of improvement of a sitting property of the seat, it is desired that an elongation rate of the planar body be changed partially so that the planar body partially largely extends to support the seat-pad portion thus strongly pressed. That is, it is desired that the planar body be partially made easily extensible, so that a sitting pressure concentrating on the seat-pad portion for supporting the occupant buttocks is dispersed, so as to achieve a more ideal distribution of the sitting pressure.
For example, in a technique described in Japanese Patent Application Publication No. 2005-46355 (JP 2005-46355 A), a seat planar support member for supporting a seat pad is attached within a seat frame. The seat planar support member includes a flexible net material as an example of a planar body of the present disclosure, and a lamination fabric material. The flexible net material is a face material having a moderate flexibility and a generally rectangular shape in a front view, and is constituted by a fabric material or a three-dimensional knit fabric including elastic yarns. Further, the lamination fabric material is a generally rectangular face material having a smaller size than the flexible net material, and its elongation percentage in a surface direction is smaller than that of the flexible net material. In the technique as known in the art, the flexible net material is provided in a stretched manner inside the seat frame and the lamination fabric material is fixed at an appropriate position of the flexible net material. This can provide a difference in elongation rate of the flexible net material between a part where the lamination fabric material is placed and a part where the lamination fabric material is not placed. In view of this, it is conceivable to improve a distribution property of a sitting pressure of a seat by applying the technique as known in the art to fix the lamination fabric material to the appropriate position of the planar body so as to partially change the elongation rate.